TodoApp.BlazorWasm.Client: CS1574 unresolved XML doc crefs for ValidationException/ConcurrencyException/generic-method overloads

[adrianhall]

Summary

While fixing #539 (missing using Microsoft.EntityFrameworkCore.Infrastructure;/.ChangeTracking causing CS1574 in sample DbContexts), building TodoApp.BlazorWasm.Client with -p:GenerateDocumentationFile=true surfaced additional, unrelated CS1574 warnings that have a different root cause (not a missing namespace import):

Services/ITodoService.cs(110,26): warning CS1574: XML comment has cref attribute 'ValidationException' that could not be resolved
Services/ITodoService.cs(151,26): warning CS1574: XML comment has cref attribute 'ConcurrencyException' that could not be resolved
Services/TodoService.cs(93,20): warning CS1574: XML comment has cref attribute 'AddAsync(T)' that could not be resolved
Services/TodoService.cs(134,42): warning CS1574: XML comment has cref attribute 'ReplaceAsync(T)' that could not be resolved
Services/TodoService.cs(180,56): warning CS1574: XML comment has cref attribute 'RemoveAsync(string, DatasyncServiceOptions)' that could not be resolved

There's also an unrelated CS1571 (duplicate param tag for title) reported alongside these in the same files.

Root cause (to be confirmed by whoever picks this up)

• ValidationException/ConcurrencyException: likely missing using for the namespace(s) where these types actually live (e.g. System.ComponentModel.DataAnnotations for ValidationException, and whatever namespace hosts the datasync client's ConcurrencyException), similar in spirit to TodoApp.Uno: CS1574 unresolved XML doc cref to DatabaseFacade.EnsureCreated #539 but for different types/files.
• AddAsync(T), ReplaceAsync(T), RemoveAsync(string, DatasyncServiceOptions): these look like generic-method/overload cref syntax mismatches against DatasyncServiceClient<T>'s actual method signatures (e.g. missing type-parameter list or mismatched parameter types), rather than a missing-using problem.

Files affected

• samples/todoapp-blazor-wasm/TodoApp.BlazorWasm.Client/Services/ITodoService.cs
• samples/todoapp-blazor-wasm/TodoApp.BlazorWasm.Client/Services/TodoService.cs

How to reproduce

dotnet build samples/todoapp-blazor-wasm/TodoApp.BlazorWasm.Server/TodoApp.BlazorWasm.Server.csproj -p:GenerateDocumentationFile=true

(The Client project builds as a dependency of Server.)

Suggested fix

Correct each cref to reference a resolvable type/member — either fix the using imports (for ValidationException/ConcurrencyException) or fix the cref syntax to match the actual method signature (for the generic-method overloads), and fix the duplicate param name="title" tag while in the area.